A voltage regulator is a circuit that ensures that the voltage requirement of a load is maintained. Often coupled directly to a microprocessor, the voltage regulator ensures that a constant voltage is available to the microprocessor, adjusting for variations in both the power consumption by the microprocessor and the input voltage. The voltage regulator may also perform voltage conversion, such as converting a 12V source voltage to a microprocessor operating voltage of 1.35V.
As microprocessor operating frequencies increase and the operating voltages decrease, the current drawn from the voltage regulator also increases. Due to imperfect power conversion, the temperature of the voltage regulator components may exceed their rated specifications. Typically, the thermal design of the system accounts for some of the heat generated by the voltage regulator, using heat sinks and fans, for example. However, overheating of the voltage regulator may still be a problem, which can shorten the product lifetime or cause premature failure.
To reduce the high cost of cooling, some designs scale back the current delivery capacity of the voltage regulator. This is justified since typical applications draw less current than the theoretical maximum available current. However, where an application draws more current, the application may not work. In any case, the voltage regulator is likely to be overstressed, become overheated, and possibly fail. Thus, scaling back the amount of current delivered by the voltage regulator is inherently risky.
Thus, a need exists for a voltage regulator that overcomes the shortcomings of the prior art.